Servicing of wells



May 20, 1969 T, w, CHILDERS ET A1. 3,444,927

SEHVICING OF WELLS Filed Nov. 21, 41967 sheet of 2 SERWCE LINE 3|INVENTORS.

THOMAS W. CHILDERS, Y EDMOND R. GENOIS,

A NEY May 20, 1969 T. w. CHILDERS ET A1. 3,444,927

SERVI C ING OF WELLS (DQ a LU 9 g fmi INVENTORS. -l THOMAS W. CHILDERS,

3 v EDMOND R. GENOIS, U- g BY FTORNEY,

United States Patent O 3,444,927 SERVICING F WELLS Thomas W. Childers,Metairie, and Edmond R. .Genom New Orleans, La., assignors to EssoProduction Research Company Filed Nov. 21, 1967, Ser. No. 684,670 Int.Cl. E21b 33/035, 43/01, 7/12 U.S. Cl. 166-.5 10 Claims ABSTRACT 0F THEDISCLOSURE Horizontally spaced apart underwater wells each having atleast two pipe strings arranged therein interconnected adjacent theirlower ends and each having a dow llne connected to the pipe strings andextending to a remote accessible location are serviced by uidlyinterconnecting the wells at a point removed from the accessiblelocation and flowing fluid into the first of the wells through its flowline and through the fluid interconnection; the fluid may be used topropel a well tool into one of the wells.

BACKGROUND OF THE INVENTION Field of the invention The present inventionis directed to servicing of wells. More particularly, the invention isconcerned with the servicing of a plurality of spaced apart underwaterwells. In its more specific aspects, the invention relates to method andapparatus for servicing and completing underwater wells wherein commonfacilities are provided for a plurality of wells.

Description of the prior art It is known to service underwater wellsusing the so-called through ow line techniques wherein well tools arepropelled into and out of a well using uid pressure to run the tools inand out of the well and through curved conduits. When such techniquesare employed, however, each well heretofore required at least two owlines to provide a circulation path to operate the through flow linecompletion and servicing system. Not only was this expensive because ofincreased capital investment but also because maintenance and operationcosts were increased. It has now been found that only one flow line isneeded for each well having a plurality of pipe strings therein byproviding in accordance with the present invention, a fluidinterconnection with another well and utilizing the interconnection andthe ow line of the second well to provide the necessary fluidcirculation path. Thus, the present invention reduces the number of fiowlines and auxiliary equipment and provides an unobvious and unexpectedresult in completion and servicing operations by utilizing commonfacilities for a plurality of wells. Thus, the flow lines whichheretofore were used for only one well may be employed for a pluralityof wells.

SUMMARY OF THE INVENTION The present invention may be briefly describedand summarized as a method for servicing underwater wells which arehorizontally spaced apart. These Wells are provided with at least twopipe or tubing strings which are interconnected adjacent their lowerends. Each well has a ow line connected to the pipe string which extendsto an accessible location, usually a production and servicing platformwhich may be supported in the water either by bottom support means or bylloating means such as a vessel or submerged buoyancy means.Alternatively, the production and servicing means may be located onshore. The wells are fluidly interconnected at a point removed from theaccessible location, preferably adjacent water bottom and fluid isflowed into the rst of said wells 3,444,927 Patented May 20, 1969through its ow line, down one pipe string and up the other and thencethrough the fluid interconnection and the flow line of the second wellto the accessible location. The uid may be used to propel a well toolinto and out of either of the wells.

The present invention also involves apparatus comprising means iluidlyinterconnecting such underwater wells as described herein to each otherat a point removed from servicing facilities and control means in theuid interconnecting means for controlling ow of uid through the fluidinterconnecting means in combination with the plurality of tubing orpipe strings and the well flow lines.

BRIEF DESCRIPTION OF THE DRAWING The invention will be furthe-rdescribed by reference to the drawing in which:

FIG. 1 is a view partly in section of a pair of spaced apart wellsillustrating a preferred mode and embodiment for carrying out theinvention.

FIG. 2 is a view illustrating the ow line connection of the wells to aremote production and servicing platform.

FIG. 3 is an enlarged fragmentary view of a portion of the platform ofFIG. 2.

FIG. 4 is a schematic view of the servicing facilities on the platform.

DESCRIPTION OF THE PREFERRED MODE AND EMBODIMENTS RELATIVE TO THEDRAWING Referring now to the drawings and particularly to FIGS. 1, 2 and3, numeral 11 designates a body of water having a Water surface 12 andwater bottom 13 which may be the ocean floor. Drilled in the waterbottom 13 is a first well 14 and a second well 15 which suitably may beoil and/or gas wells. Well 14 has a casing 16 cemented in place bycement sheath 17. Well 14 is provided with a first tubing or pipe string18 and a second tubing or pipe string 19 which are interconnectedadjacent their lower ends by fluid interconnection means 20.

Well 15 has a casing 21 arranged therein and cemented with cement sheath22. Well 15 is provided with a tubing or pipe string 23 and a secondtubing or pipe string 24 which are interconnected by fluidinterconnection means 25.

The lower end of pipe string 18 has an opening 26 and the lower end ofpipe string 24V has an opening 27.

The wells 14 and 15 and the casings 16 and 21 have been perforated in aproducing formation 28 from which oil and/or gas may be produced byperforations 29 in well 14 and performations 30 in Well 15.

The tubing strings 18 and 19 and 23 and 24 are fluidly interconnected bya service line 31 provided with valve control means 32 and 33. A flowline 34 connects to the service line 31 and to the tubing strings 18 and19 and a second ow line 35 connects to the service line 31 and to thetubing or pipe strings 23 and 24. The tubing strings 18 and 19 arecontrolled by means of valve control means 36 and 37 while the tubing orpipe strings 23 and 24 are controlled by valve control means 38 and 39.

The flow lines 34 and 35 extend to a platform 40 (FIG. 2) on which arelocated production and servicing facilities -generally indicated `by thenumeral 41. As shown in FIG. 4, the production and servicing facilitiesmay include storage means such as tankage 42. Lines 43 and 44 connectrespectively to lines 34 and 35; by providing pump means 70, which isconnected by branch lines 45 to lines 43 and 44 and well tool insertionmeans 46 and by suitable manipulation of valves 47, 48 49, 50, 51 and52, it is possible to pump into and out of the wells 14 and 15 andpropel well tools into and out of the wells 14 and 15. Pump means 70 isalso connected to tankage 42 by maniold 71 provided with valves 72.

In accordance with the present invention, it may be desirable to run awell tool such as a tubing extension member 53 into the Well 14 throughtlow line 34 as shown in FIG. 1. Under these circumstances, inaccordance with the present invention, the tubular extension mem- =berprovided with a sealing means 54 which acts as a piston, may be insertedin the well insertion means 46 (FIG. 4) and introduced through line 43into a flow line 34 by means of uid pumped thereinto. The tubularextension member travels through the production ow line 34 (FIG. 2)around the radius bend 55 and down the tubing string 18 to be seated ina landing nipple 56 above the fluid interconnection 20 such that thetubing extension 53 extends below the opening 26 which will allow theintroduction of a suitable well servicing uid into it adjacentperforations 29. The fluid interconnection 20 and the service line 31.and the ow line 35 provide a circulation path for the fluid which isflowed down the pipe or tubing string 18. Of course, it is understoodthat the valves 36, 37 and 33 are open and valves 38 and 39 and 32 areclosed during this operation. When it is desired to remove well toolssuch as tubing extension 53, the ow is reversed. To this end the valves38 and 39 and 32 remain closed and valves 33, 36 and 37 remain open.Fluid is flowed down the iiow line and through the service line 31 anddown the tubing or pipe string 19 against the piston 54 which causes itto be released from the landing nipple 56 and to travel up- Wardlythrough the tubing or pipe string 18 and thence to the production andservicing facilities 41 through How line 34.

The production or servicing facilities 41 may suitably be located on aplatform supported by structure 61 on water bottom 13 as shown in FIGS.2 and 3. The platform 40 may also be on shore or it maybe supported by afloating vessel or by submerged buoyancy means such as the seadrometype. With respect to the particular embodiment of FIG. 2, however, theow lines 34 and 35 are brought to the platform 40 by liow line risers 62which may suitably be installed on a rail 63 (FIG. 3) such as describedin U.S. Patent 3,226,728 issued in the name of J ames G. Walvoord.

The valves 32, 33, 36, 37, 38, and 39 are, of course, inaccessible fromthe surface; therefore, it is necessary to operate these valves remotelyfrom an accessible location such as the platform 40. To this end, lines65, 66, and 67 may be connected to valves 32, 36, and 37, respectively,and similar lines may be connected to valves 33, 38, and 39. These linesmay be electrical connecting means or pneumatic or hydraulic lines tooperate the service valves. These lines 65, 66, and 67 may extend to theplatform 40 for operation of the valves as may be desired. The remoteoperation of such valves is Well known and a description of suchremotely operated valves may be found in Composite Catalog 1964-65,volume I, page 1230 (Cameron Iron Works, Inc. Fail Safe Valves).

While a plurality -of control lines 65, 66 and 67 have been described,it is to be -understood that one line controlled from the platforms maybe used to operate valves 32, 33, 36, 37, 38 and 39 by pilot or selectorswitches at the Christmas tree to operate the proper valve or uponreceiving a signal. The control lines may be eliminated by usingacoustically controlled valves which require no physical connection withthe platform.

It will be manifest that the present invention is quite advantageous anduseful in that it eliminates the number of lines and, therefore,investment, maintenance, and operating costs over that heretoforerequired.

As an example of the present invention, in a 40 acre spacing of wells,paired well such as 14 and 15 may be about 1300 feet apart; therefore,the service line 31 may be about 1300 feet long. The flow linerequirements for two wells such as 14 and 15 from a production platformsuch as 40 may be about 4.25 miles with underwater flow line connectionstotaling six in number. The present invention, by reducing the mileageof flow lines underwater connections and the number of risers, allowsthe obtaining of marked and unobvious advantages.

The well servicing fluids employed in the present invention may includeby Way of illustration and not by way of limitation, cement slurriesdrilling muds, oil and water emulsions, perforating fluids such as gelsand the like, and stimulating liquids such as hydraulic fracturingliquids, acids, solutions of surfactants in oil and/or water, aqueous oroily solutions of corrosion inhibitors and the like, liquid sandconsolidation uids such as resins, etc., and slurries of clay,bentonite, and other similar materials.

The well tools which may be run into and out of the Wells, in accordancewith the present invention, include by way of illustration and not byway of limitation, tubular extension members, logging tools and sondes,bottom hole pumps, rbottom hole pressure measuring devices, and thelike.

The nature and objects of the present invention having been completelydescribed and illustrated and the best mode and embodiment contemplatedset forth what we wish to claim as new and useful and secure by LettersPatent is:

1. A method for servicing at least first and second horizontally spacedapart underwater wells each having at least two pipe strings arrangedtherein interconnected adjacent their lower ends and each well having .aoW line connected to said pipe strings and extending to an accessiblelocation, which comprises:

fluidly connecting said wells to each other at a point removed from saidaccessible location; and

owing uid into the tirst of said Wells from said' accessible locationthrough its ow line down one pipe string and up the other and thencethrough said lluid interconnection and the ow line of said second wellto said accessible location.

2. A method in accordance with claim 1 in which a well tool is insertedinto the ow line of said first well at said accessible location and runinto said well with said fluid.

3. A method in accordance with claim 2 in which the well tool is removedfrom said well by owing uid through the tiow line of the second well,through said fiuid interconnection, down the other pipe string and upthe one pipe string of the first well, and thence through the flow lineof the first well to the accessible location.

4. A method in accordance with claim 1 in which the wells are iiuidlyinterconnected at a point adjacent water bottom.

5. A method in accordance with claim 1 in which the fluid flowed intothe first of said wells is a servicing iiuid.

6. A method in accordance with caim 1 in which the fluid is cement.

7. A method in accordance with claim 1 in which the accessible locationis a production platform horizontally spaced from said wells.

8. In a well servicing system comprising at least first and secondhorizontally spaced apart underwater wells each having at least two pipestrings arranged therein interconnected adjacent their lower ends andeach having a flow line connecting to said pipe strings and to servicingmeans horizontally spaced from said Wells, apparatus which comprises:

conduit means fluidly interconnecting said Wells to each other at apoint removed from said servicing means; and

control means in said uid interconnecting means for controlling the flowof fluid through said uid interconnecting means.

9. Apparatus in accordance with claim 8 in which the control meanscomprises valve means operated from said servicing means for controllingow of uid into 3,136,363 6/ 1964 Yetman et ai 166-95 X and out of saidWells. 3,139,928 7/1964 Broussard 166-2 10. Apparatus in accordance withclaim 8 in which 3,331,753 5/1968 Fredd 166 154X the fluidinterconnecting means is a conduit connected to said wells at a pointadjacent water bottom. 5 CHARLES E. OCONNELL, Primary Examiner.

References Cited J. A. CALVERT, Assistant Examiner. UNITED STATESPATENTS U-'S- CL X-R- 3,003,560 10/1961 `Corley et al. 166-.5 X 166-46,52

3,111,692 11/1963 Cox 166-.5 X 10

